1. Field of the Invention
The present invention relates to a manual operation device for operating an in-vehicle apparatus.
2. Description of Related Art
In general, a vehicle includes various in-vehicle apparatuses, such as an air conditioning apparatus, an audio apparatus, a navigation apparatus. For example, the air conditioning apparatus has various operational modes, such as a foot mode, a face mode, a defroster mode. A driver of the vehicle manually operates a lever, a knob or a button to select one of the operational modes. The selection of the operational mode is generally performed by moving (sliding) the lever, rotating the knob or depressing the button.
Various attempts have been made to improve operational feeling of the lever, the knob or the button. For example, as shown in FIG. 12, a manual operation device recited in Japanese Unexamined Patent Publication No. 2002-189557 (corresponding to U.S. Pat. No. 6,591,175) includes an operation member 200, an actuator 202, a control arrangement 204, a sensing member 206 and an input/output member 210. The actuator 202 applies external force to the operation member 200. The control arrangement 204 controls operation of the actuator 202. The sensing member 206 senses an operational state of the operation member 202. The input/output member 210 communicates signals with an in-vehicle apparatus (i.e., a vehicle mounted apparatus) 212 installed in the vehicle. An external signal of a sensing means (not shown), which is connected to the in-vehicle apparatus 212, is inputted to the control arrangement 204. Then, the control arrangement 204 generates a corresponding predetermined control signal. Operation of the actuator 202 is controlled based on the control signal.
The manual operation device recited in Japanese Unexamined Patent Publication No. 2002-189557 is intended to provide different operational feelings through the operation member 200 based on a state of the in-vehicle apparatus 212. For example, when drive force for driving the operation member 200 needs to be changed, the amount of the driving force, an applying direction of the driving force and a load applying time period are taken into account.
However, an operational work load of the driver is not taken into account in the manual operation device recited in Japanese Unexamined Patent Publication No. 2002-189557. In a parked state of the vehicle, when the driver operates the operation member 200, the driver can concentrate on the operation of the operation member 200. Thus, it is desirable to operate the operation member 200 with a relatively small drive force in the parked state of the vehicle. Contrary to this, in a driving state of the vehicle, the driver needs to concentrate on maneuvering of the vehicle and thus can only provide small attention to the operation of the operation member 200. Thus, when the operation member 200 can be operated with the relatively small drive force in the driving state of the vehicle, the driver may not notice activation of the operation member 200. This might cause inadvertent incorrect operation of the operation member 200. In order to prevent the inadvertent incorrect operation of the operation member 200, it is desirable to make the operation member 200 only operable with a relatively large drive force in the driving state of the vehicle.